Voice recognition systems have been used in a wide range of fields, providing various functions required by users. Voice recognition techniques may be implemented in electronic devices including voice input devices (for example, microphones). Such voice recognition techniques have recently replaced physical inputs of electronic devices, and are becoming an increasingly popular way to control the electronic devices by voice.
In general, voice recognition may be roughly divided into two operations, preprocessing and recognition. For example, a conventional voice recognition technology may analyze an input voice, extract features of the input voice, and measure similarity with a previously collected voice model database to convert the most similar extracted features into characters or commands. The user's voice often includes meaningless sounds such as ambient noise. Thus, the voice recognition system may determine the extracted voice recognition section.
For instance, when the user wakes up the voice input device using a voice start button or a call instruction, the voice input device (e.g., microphone) may be opened. Then, background energy may be used to estimate start and end points of the voice uttered by the user. When the end point of the uttered voice is detected, the voice input device may be closed.
The voice recognition system may analyze the voice through a preprocessing operation to extract features for voice recognition. The voice recognition system may compare the input voice with the voice database to output the most likely word(s) as a result of voice recognition.
In addition, the voice recognition system may convert the recognized result into sound, and notify the user by sound. Alternatively, the voice recognition system may notify the user by displaying the result.
However, when a user who is not skillful in the use of the voice recognition system is not acquainted with the recognizable vocabulary, the user may be inconvenienced due to uttering an incorrect command. As an example, if the a utters the command, “Starbucks at Gangnam station”, but realizes the utterance of the wrong command, and then reutters “Ah no, it's not . . . ”, a conventional voice recognition system may detect “Starbucks at Gangnam station” as an end point and then close the voice input device. Thus, the voice recognition system may retrieve information on “Starbucks at Gangnam station” and output the result. This may cause inconvenience by forcing the user to wait for retrieval of the unwanted information on “Starbucks at Gangnam station” prior to re-uttering a new command in order to acquire the user's desired information.
Alternatively, if the conventional voice recognition system recognizes the command “Starbucks at Gangnam station . . . Ah no, it's not . . . ”, the system may fail to retrieve corresponding information as the command does not exist in the voice recognition system.